Add support for most recent PHP version

Author: henriquemoody

.github/workflows/continuous-integration.yml

@@ -102,4 +102,4 @@ jobs:
         run: composer check-style
 
       - name: Run static analyse
-        run: composer psalm
+        run: composer psalm

src/AbstractDatabase.php

@@ -50,8 +50,8 @@ abstract class AbstractDatabase implements \Iterator, \Countable
      * @throws \RuntimeException when base directory not specified and directory can not be located automatically
      */
     public function __construct(
-        string $baseDirectory = null,
-        TranslationDriverInterface $translationDriver = null
+        ?string $baseDirectory = null,
+        ?TranslationDriverInterface $translationDriver = null
     ) {
         if (empty($baseDirectory)) {
             // Require external database in "sokil/php-isocodes-db-*" packages

src/IsoCodesFactory.php

@@ -61,8 +61,8 @@ class IsoCodesFactory
     private $translationDriver;
 
     public function __construct(
-        string $baseDirectory = null,
-        TranslationDriverInterface $translationDriver = null
+        ?string $baseDirectory = null,
+        ?TranslationDriverInterface $translationDriver = null
     ) {
         $this->baseDirectory = $baseDirectory;
         $this->translationDriver = $translationDriver ?? new GettextExtensionDriver();